Tuesday, April 24, 2007

Water

Water shortages have again hit the news in Australia, with the announcement that without significant rains in the next six to eight weeks, irrigators on the crucial Murray-Darling system will not receive any water allocations, threatening millions of dollars of agricultural production. Around 40% of our food comes from this region, an enormous catchment covering most of the eastern states west of the Great Dividing Range. But rainfall is very erratic, and most of the region is presently in the worst drought in a hundred years. This may or may not have something to do with climate change.

Closer to home, Warragamba dam (Sydney's major water source) is still below 40% - despite heavy rain yesterday and more today, most of which missed the catchment area (spare a thought - and prayer - for Brisbane, of course, with dam levels below 20% last time I heard).

The need for water crosses cultural boundaries and underscores our shared humanity. Clean drinking water remains one of the major global divides between rich and poor. Over a billion people lack access to safe water and according to some estimates up to 80% of human sickness is the result of drinking poor water.
Twelve points if you can name the country containing this aqueduct. Photo by HCS.

16 comments:

Mikhaela said...

I have had to to take off my shoes on several occasions in the last two days just to cross some very flooded major city intersections...

Morris should recycle it. The concrete doesn't need it.

Doug Forbes said...

When we did a presentation to school kids recently on becoming civil engineers we asked them what they thought the most likely source of war in the comming decades would be over... oil?...land? We then suggested that it is most likley to be over water. It is quite concerning really.

Doug F.

PS- we then proposed that it is civil engineers who can address supplies of clean water world wide... I suppose it just needs government support (and money).

Mister Tim said...

We drove along a decent section of the Murray River on our way to and from Adelaide in early Febrruary. We were pretty shocked to see in some towns residences and businesses watering their lawns with big sprinklers during the day - and the whole areas was so green. I feel for the farmers who have no water, but perhaps the towns along the Murray should share some of the blame.

Mister Tim said...

I don't know where the acqueduct is, but it looks as though you need to remove some dust from your scanner (or from the original negative or photo - it looks like negatives I scan when I haven't cleaned them properly or before photoshop).

byron said...

Tim - unfortunately, it's not a scanner problem, but blemishes on the original, which is quite old. This is a hint for the points, for those who have been paying attention.

Doug - yes, I was going to add another paragraph about the role of governments and engineers (that is, the primary problem in most countries is quality rather than quantity (or quantity of quality water)) and this is one area in which technology and funding can make a very large difference. The global 'water crisis' (language used by the UN) is more complex than this, but millions could be fairly straightforwardly helped with some engineering expertise and money.

Mikhaela - We have certainly had some of very well moisturised roads in the last couple of days.

Anthony said...

On the basis of recent attributions, I'm going for Israel.

What I'd really like in the news is someone to tell us how dam levels compare to a year ago - surely that's a fairly significant stat? My gut feeling is that they've held ok over the twelve months, and a decently wet winter could see the tide turn. Pun intended, of course.

Mister Tim said...

I also wonder if our forms of agriculture could be improved, i.e. should we be growing different crops and focusing on different types of food; minimise our use of crops that are more heavily water-dependent, e.g. cotton.

Also, I was under the impresion that the majority of vegetables consumed by Sydney were grown in the green belt around Sydney, from Cambelltown up towards the lower Blue Mountains; perhaps the Murray-Darling irrrigation area is the primary source for the rest of the country, and also for fruit.

re the photo: If you send me an original scan of the photo I'll send it back to you in considerably better condition (offer goes for as many photos as you would like cleaned up, within reason).

byron said...

Anthony - twelve points. I shouldn't have made it so obvious. The aqueduct is just outside the Roman port city of Caesarea.

And here is a graph of Warragamba dam levels since its construction in 1960 (see the second page of the pdf).

Anthony said...

It was the rss feed that acted as a tip off, rather than any hints you left...if that helps ease the pain ;-)

Thanks for the link - so there has been at least a halt in the slide, though I like the way they put the asterisk on the final figure without explaining the significance of the deeper access installed recently.

What was especially interesting is how the last few times, the recovery has been within a year. I don't recall living through the great flood, but there you go.

byron said...

Tim - yes, by 'our' food, I meant Australia rather than Sydney.

Anthony - it was the rss feed I had in mind, since I remembered that my father took these photos of Israel (I took some as well, but I took prints while he took slides and it is the slides that he has recently scanned. Tim, the blemishes are on the original slides, though thanks for your offer to clean them up) and so added the credit to them all at the same time, thus giving you the tip-off.

I remember reading about the significance of the deeper access somewhere. Basically, they've recently expanded the 'capacity' of the dam by putting access pipes lower down in the dam wall, so more of the stored water is available for use.

And yes, recovery in the past has usually taken months rather than years - it all depends on sustained heavy rainfall in the catchment. But it is precisely this pattern that is becoming more questionable, possibly rarer, with climate change.

Interestingly, I heard on the radio yesterday that rainfall in the SE of Australia has been about average this last quarter, but flows in the Murray-Darling remain critically low. They suggested this was because (a) drought-affected plants are thirstier than before, leading to more transpiration, and (b) the ground is warmer than before, leading to more evaporation.

Toby said...

Anthony, week by week dam levels, and a comparison to the last calendar year can be found at the SMH weather.

byron said...

Thanks Toby.

Sarah said...

How sad that I only just now discovered your blog, Byron, and even that by the chance reading of a forwarded email via Victor Shaw of your CASE course. It is sad in that had I seen this photo earlier I would have had points of my own... I not only know that it is a photo of Israel because of any RSS feeds, but from the familiarity of the scene as my own photo of the same aqueduct has sat on my bookshelf for years!

Sarah.

byron said...

Sarah - good to hear from you. Hope you're well. I'm sure they'll be some points for you soon enough.

byron smith said...

Guardian: Water in the Middle East.

byron smith said...

SMH: Warragamba finally at 100%. Last time it was full was 1998.